An interventional study of Endovascular treatment with profunda femoris vein thrombosis clearance (Endovascular treatment with PFV-TC) and Percutaneous mechanical thrombectomy without profunda femoris vein thrombosis clearance (PMT without PFV-TC) in Deep Vein Thrombosis, sponsored by RenJi Hospital. Recruiting at 1 site in China. Open to participants aged 18 Years to 85 Years. Per ClinicalTrials.gov, last updated 2026-10-13.
Sponsored by RenJi Hospital · Not applicable, Interventional, and Treatment
Patients with iliofemoral vein thrombosis are prone to developing post-thrombotic syndrome (PTS). The profunda femoris vein (PFV) is an important inflow of the iliofemoral vein. Profunda femoris vein thrombosis clearance (PFV-TC) may improve the patency of iliofemoral vein and reduce the occurrence of PTS.
Acute lower extremity deep vein thrombosis (DVT) can lead to obstruction of veins, causing sudden lower limb swelling. Patients may also develop post-thrombotic syndrome (PTS) manifesting as recurrent lower limb swelling, skin disorders, and even non-healing ulcers, which severely affects the patient's quality of life. Among lower extremity DVT, thrombosis involving the iliofemoral veins is the most severe, with an incidence of PTS as high as 20%-50%. According to the results of a prospective clinical study, rapid endovascular thrombus removal can effectively improve the primary thrombus clearance rate and shorten hospital stay in patients with DVT. Among 329 patients, 192 (58.5%) achieved complete thrombus removal using the AngioJet catheter. This therapy was once considered to be the first-line treatment option for DVT. However, the results of the ATTRACT study, published in 2017 in New England Journal of Medicine found that there was no significant difference in the incidence of PTS at two years after pharmacomechanical catheter directed thrombolysis (PCDT) compared with anticoagulation alone. Although PCDT can rapidly remove thrombus, is it unable to improve the long-term outcomes for patients with DVT? According to previous studies, the primary patency rate at 12 months after PCDT for acute iliofemoral venous thrombosis ranges from 77% to 85%, while the incidence of PTS at 24 months postoperatively is as high as 40%. Residual thrombus is an important cause of thrombus recurrence, re-occlusion of the vein, and poor clinical outcomes. Previous studies have primarily focused on thrombus clearance in the popliteal vein, superficial femoral vein, common femoral vein, and iliac vein, while neglecting the assessment and clearance of profunda femoris vein (PFV) thrombosis. As the PFV is an important inflow of the iliofemoral vein, whether PFV-TC can improve the patency rate and clinical outcomes of endovascular treatment for acute iliofemoral DVT remains unclear. In a preliminary study, the investigators analyzed and compared two cohorts: one receiving conventional endovascular treatment for acute iliofemoral venous thrombosis, and the other receiving conventional treatment combined with profunda femoris vein thrombosis clearance (PFV-TC). The results showed that the 24-month patency rate of the iliofemoral vein was 90% vs. 72%, and the incidence of PTS was 11% vs. 32% (P=0.020). These findings were published in November 2025 in European Journal of Vascular and Endovascular Surgery. This study has garnered widespread attention, and de Wolf MAF published an invited commentary on this study, acknowledging the value of this approach in the endovascular treatment of acute iliofemoral DVT. Therefore, the investigators hypothesize that PFV-TC can improve inflow and reduce the incidence of PTS for iliofemoral DVT. However, high-level evidence is still lacking. The PROTECT study is a prospective, multicentre, randomised, open-label, outcome assessor-blinded, 1:1 parallel-group controlled clinical trial evaluating the efficacy and safety of PFV-TC in patients with acute iliofemoral DVT and PFV involvement, which aims to determine whether PFV-TC can reduce the incidence of PTS and provide clinical decision-making in this specific population.
785 studies on the registry are indexed under Venous Thrombosis; 110 are open to participants now.
This study's planned enrollment of 140 is close to the median of 152 across 477 interventional studies indexed under Venous Thrombosis.
Browse Venous Thrombosis studies →RenJi Hospital is the lead sponsor of 550 studies on the registry; 247 are open to participants now.
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The criteria were revised on the registry on Oct 13, 2026. See what changed
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Creatinine clearance (CrCl)
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Endovascular treatment with PFV-TC group (experimental group)
Procedure: Endovascular treatment with profunda femoris vein thrombosis clearance (Endovascular treatment with PFV-TC)
Endovascular treatment without PFV-TC group (control group)
Procedure: Percutaneous mechanical thrombectomy without profunda femoris vein thrombosis clearance (PMT without PFV-TC)
Endovascular treatment with PFV-TC group (experimental group): Based on the control group, access is obtained via the contralateral common femoral vein using a crossover technique, or via a popliteal-profunda communicating vessel approach to PFV. The thrombus status of the PFV is assessed, and rapid thrombus removal is performed on the PFV thrombosis.
An appropriate puncture approach is selected, including the ipsilateral calf vein, ipsilateral popliteal vein, or ipsilateral femoral vein. Under ultrasound guidance, a vascular sheath is inserted after puncture, and systemic heparinization is performed. Using a guidewire and catheter, the guidewire is advanced antegradely into the inferior vena cava to establish a pathway. Operators may use any device capable of rapid endovascular thrombus removal such as the AngioJet catheter (Boston Scientific, USA) and the Indigo catheter (Penumbra Inc, USA). However, catheter-directed thrombolysis (CDT) alone and the ClotTriever (Inari Medical, USA) is not permitted. After thrombus removal, the outcome is evaluated by venography. If iliac vein stenosis greater than 50% is detected, balloon dilation is performed using a balloon matched to the normal vessel diameter. If residual stenosis remains greater than 50% after balloon dilation, stent implantation is performed.
Incidence of Post-Thrombotic Syndrome (PTS)
Assessed by the Villalta score. The Villalta scale is the recommended tool for diagnosing and grading the severity of PTS. It is a composite score based on 11 items (5 patient-reported symptoms and 6 clinician-assessed signs), each rated from 0 (absent) to 3 (severe), yielding a total score ranging from 0 to 33. A score of 0-4 indicates no PTS, whereas a score of ≥5 or venous ulcer confirms the diagnosis of PTS. Specifically, scores of 5-9 indicate mild PTS, 10-14 indicate moderate PTS, and a score of ≥15 or venous ulcer indicates severe PTS. Higher scores reflect greater disease severity.
Time frame: at 24 months
Incidence of moderate-to-severe PTS
Assessed by the Villalta score
Time frame: at 6, 12, and 24 months
Patency rate of the ipsilateral iliofemoral vein
Assessed by color Doppler ultrasound and defined as respiratory phasic flow with stenosis \<50% and no pathological collateral veins.
Time frame: at 12 months and 24 months
Incidence of PTS
Assessed by the Villalta score
Time frame: at 6 and 12 months
Recurrence rate of symptomatic Deep Vein Thrombosis (DVT)
Assessed by symptoms combined with ultrasound examination in the ipsilateral limb
Time frame: at 24 months
Rate of re-intervention
Assessed by documentation of clinical reintervention
Time frame: at 24 months
Quality of life score
Assessed by Venous Insufficiency Epidemiological and Economic Study Quality of Life questionnaire (VEINES-QOL). The minimum value is 0 and the maximum value is 100. Higher score means a better outcome.
Time frame: at 6, 12, and 24 months
Incidence of major bleeding
Defined by International Society on Thrombosis and Haemostasis (ISTH) criteria
Time frame: at 24 months
Incidence of symptomatic Pulmonary Embolism (PE)
Assessed by symptoms combined with contrast-enhanced computed tomography examination
Time frame: at 24 months
Incidence of symptomatic Venous Thromboembolism (VTE)
Assessed by symptoms combined with ultrasound and contrast-enhanced computed tomography examination
Time frame: at 24 months
All-cause mortality
All-cause death
Time frame: at 24 months
Plan to share: Yes — De-identified individual participant data, the study protocol, and the statistical analysis plan will be available beginning 3 months and ending 5 years after article publication to researchers who provide a methodologically sound proposal.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report, Analytic code
Time frame: Information will be available beginning 3 months and ending 5 years after article publication.
Access criteria: De-identified individual participant data will be available to researchers who provide a methodologically sound proposal and sign a data use agreement.
No publications or documents are linked to this record.
Started Jun 2026 (actual). Primary completion is estimated for Jun 2029, 36 months after the start.
Of 99 non-industry interventional studies with no phase under Venous Thrombosis, half reached primary completion within 35 months of starting (the median), counting those still running; a quarter within 13 and three quarters within 57. This study's planned 36 months is close to that.
Counting every sponsor, half of 117 studies reached it within 34 months; a quarter within 13 and three quarters within 56.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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